WASHINGTON — President Obama and Russian leader Vladimir Putin, whose relationship is strained at the best of times, meet tomorrow on Russian soil as the United States, over Putin’s protests, threatens to attack Syria.

The antagonism between the two men is likely to surface at this week’s summit in St. Petersburg, where the Russian strongman and former KGB colonel is hosting the world’s preeminent powers at the two-day G-20 summit on his home turf.

“I really think these two guys, Mr. Putin and Mr. Obama, don’t like each other at all,” said Andrew Kuchins of the Center for Strategic and International Studies in DC.

“One thing is clear to me — that this is the worst personal relationship between US and Russian, perhaps even US and Soviet, leaders in history,” he told Agence-France Post.

The tension will be even greater now that Obama has said the US should take military action against Syria .